The invention is generally directed to toner and developer compositions, and more specifically, the present invention is directed to developer and toner compositions containing styrene based copolymers wherein one of the components is a terpene, such as myrcene, and optional charge enhancing additives, which impart or assist in imparting a positive or negative charge to the toner resin particles and enable toners with rapid admix characteristics. In one embodiment, there are provided in accordance with the present invention toner compositions comprised of styrene terpene resin particles, pigment particles, and optional charge additives, such as quaternary ammonium bisulfates, including distearyl methyl hydrogen ammonium bisulfate. In one embodiment, the present invention is directed to toners with charge additives of tetraalkylammonium sulfonates such as dimethyl distearyl ammonium alkyl, or perfluoralkyl sulfonates. The aforementioned toners in embodiments of the present invention enable, for example, toners with desirable melting characteristics, such as mininum fixing temperatures of between 120.degree. C. and 155.degree. C. with rapid admix of less than about 15 seconds, extended developer life, stable electrical properties, high image print quality with substantially no background deposits, and compatibility with fuser rolls including Viton fuser rolls. Other advantages of the toners of the present invention in embodiments as compared to toners with styrenemethacrylate include superior vinyl offset properties, and relative to styrene/butadiene toners improved brittleness properties, for example, the toners of the present invention in embodiments are less brittle at number average molecular weights (M.sub.w) of 50,000 to 60,000 and thus can provide improved results in the the known crease test. The crease test is a method by which the minimum fix temperature of a toner is determined. The toner is applied to paper, fused and then creased with a given load. The thickness of the resulting crease determines the minimum fix temperature of the toner. Other advantages of the toners of the present invention compared to toners of styrene-butadiene in embodiments include ease of preparation of the bulk resin used to prepare the toner compositions. The butadiene monomer is a toxic volatile gas which requires special procedures and equipment for its handling. Terpenes and related monomers are relatively non-toxic liquids that may be obtained from natural renewable nonpetroleum sources as described in, for example, the Journal of Applied Polymer Science, Vol. 46, p. 389, 1992. For example, myrcene of the formula CH.sub.2 .dbd.CH--C(=CH.sub.2)--CH.sub.2 CH.sub.2 CH.dbd.C(CH.sub.3).sub.2, may be obtained from turpentine which in turn is obtained from sulfite wood-pulping processes. Also, the aforementioned toner compositions usually contain pigment particles comprised of, for example, carbon black, magnetites, or mixtures thereof, cyan, magenta, yellow, blue, green, red, or brown components, or mixtures thereof thereby providing for the development and generation of black and/or colored images. The toner and developer compositions of the present invention can be selected for electrophotographic, especially xerographic imaging and printing processes, including color processes.
Toner compositions with styrene resins, like styrene methacrylates, styrene acrylates, styrene butadienes and charge enhancing additives, which impart a positive charge to the toner resin, are known. Thus, for example, there is described in U.S. Pat. No. 3,893,935 the use of quaternary ammonium salts as charge control agents for electrostatic toner compositions the disclosure of which is totally incorporated by reference. There are also described in U.S. Pat. No. 2,986,521 reversal developer compositions comprised of toner resin particles coated with finely divided colloidal silica. According to the disclosure of this patent, the development of electrostatic latent images on negatively charged surfaces is accomplished by applying a developer composition having a positively charged triboelectric relationship with respect to the colloidal silica.
Also, there is disclosed in U.S. Pat. No. 4,338,390, the disclosure of which is totally incorporated herein by reference, toner compositions containing styrene methacrylate, styrene acrylate and the like resins, and as charge enhancing additives organic sulfate and sulfonates, which additives can impart a positive charge to the toner composition. Further, there is disclosed in U.S. Pat. No. 4,298,672, the disclosure of which is totally incorporated herein by reference, positively charged toner compositions with resin particles of, for example, styrene methacrylate, and pigment particles, and as charge enhancing additives alkyl pyridinium compounds. Additionally, other documents disclosing positively charged toner compositions with, for example, styrene methacrylates, and charge control additives include U.S. Pat. Nos. 3,944,493; 4,007,293; 4,079,014 4,394,430, and 4,560,635 which illustrates a toner with a distearyl dimethyl ammonium methyl sulfate charge additive.
Moreover, toner compositions with negative charge enhancing additives are known, reference, for example, U.S. Pat. Nos. 4,411,974 and 4,206,064, the disclosures of which are totally incorporated herein by reference. The '974 patent discloses negatively charged toner compositions comprised of resin particles of, for example, styrene methacrylates, pigment particles, and as a charge enhancing additive ortho-halo phenyl carboxylic acids, Similarly, there are disclosed in the '064 patent toner compositions with chromium, cobalt, and nickel complexes of salicylic acid as negative charge enhancing additives.
In a patentability search there was noted the following patents, 2,986,521, 3,041,169, 3,060,019, 3,510,338, and 3,965,022, which disclose terpene homopolymers and blends of terpene homopolymers with other polymers or copolymers to formulate toner resins and developer compositions thereof. Carlson in U.S. Pat. No. 2,940,934 generally discloses copolymers of styrenes (col 3 line 6) and blends of styrene, polymers and other homopolymers, including terpene homopolymers (reference col. 6, line 6).